Indexable composite cutting insert having corner cutting edges

Abstract From the Canadian patent

An indexable composite cutting insert which is generally polygonal in plan view and includes spaced upper and lower surfaces, is composed of a core such, as a SiC-Si composite material, with the corners along one surface of the composite cutting insert being made of a superhard material of diamond or cubic boron nitride crystals bonded to the core. The limited use of superhard crystals in the critical areas of the cutting edges of the insert results in significant cost savings both, in manufacturing costs and costs of materials as well, as minimum warpage of the insert. In addition improved, wear resistance of the cutting edges of the insert is obtained.